This invention relates generally to conveyor chains for conveyor systems, for example, for a system like that disclosed in the patent to Czarnecki et al, U.S. Pat. No. 3,435,780, issued Apr. 1, 1969, and assigned to the assignee of this application. As shown in the above patent, conveyor chains are conventionally driven by driving members disposed on opposite sides of the chain which engage the arcuate surfaces of rollers carried by the chain. In some installations, for example, in foundries where the conveyor assembly may carry heavy molds between various levels of the foundry, very large driving forces are required to move the conveyor assembly. With large driving forces, the arcuate surfaces of the rollers develop laterally-outward forces tending to spread the driving members. In addition to the above undesirable tendency, the force of the driving members against the rollers is generally detrimental to the life of the bearings for the rollers. As a still additional disadvantage, the rollers must be sufficiently large in diameter to extend laterally outwardly of the driving members to provide a substantial surface component which is crosswise of the chain to efficiently receive the force of the driving members. As a result, the rollers tend to engage the guides for the chain during chording of the chain when a curved path of relatively small radius is negotiated.
The present invention solves the above problems by providing a laterally extending driven member or block on the chain which has flat surfaces disposed crosswise of the chain for engagement by the driving members of the drive means. Accordingly, substantially no laterally-outward forces are developed, and consequently, there is no tendency to spread the driving members. Furthermore, since the crosswise flat surfaces of the driven members may readily extend to the lateral extremities of the driven members, the driven members may be constructed with a lesser extension laterally of the chain than rollers used for this purpose so as to avoid engagement of the driven members with the guide rails of the chain during chording of the chain as it negotiates a curved path. Additionally, the bearings for the rollers no longer receive the driving force thereby providing increased roller bearing life. Preferably, the driven members are pivotally mounted to the chain so as to accommodate any angular misalignment between the driving members and driven members. Also, preferably, the driven members are mounted intermediate the pivot for the chain so that they may be removed for replacement or repair without dismantling of the chain.
In view of the above and the following detailed description of the preferred embodiment of this invention, it will be appreciated that the improved conveyor chain provided by this invention is a significant advance in this art.